When digital imaging is considered for law enforcement, the concern of the admissibility of digital photographic evidence in court is often raised. The fact that digital photographs are more easily altered than film-based photographs is usually cited. Some even believe digital photographs are not admissible in court.

This article is presented in the hope of clearing up some of the confusion and misinformation about this issue. We will begin with the rules of evidence regarding digital evidence.

The Federal Level

Federal Rules of Evidence, Article X (Contents of Writings, Recordings and Photographs), Rule 101(1) defines writings and recordings to include magnetic, mechanical or electronic recordings. Rule 101(3) states that if data are stored in a computer or similar device, any printout or other output readable by sight, shown to reflect the data accurately, is an "original". Rule 101(4) states that a duplicate is a counterpart produced by the same impression as the original…by mechanical or electronic re-recording, … or by other equivalent techniques which accurately reproduces the original. And Rule 103 (Admissibility of Duplicates) states a duplicate is admissible to the same extent as an original unless (1) a genuine question is raised as to the authenticity of the original or (2) in the circumstances it would be unfair to admit the duplicate in lieu of the original. This means a photograph can be stored digitally in a computer, that a digital photograph stored in a computer is considered an original, and any exact copy of the digital photograph is admissible as evidence.

The State Level

Check your state's rules of evidence for specifics on the admissibility of digital photographs. Most states have laws that apply to digital evidence.

As an example, California Evidence Code Section 1500.6(a) (Admissibility of Printed Representation of Images Stored on Video or Digital Media to Prove Existence and Content of Image) states a printed representation of an image stored on video or digital media shall be admissible to prove the existence and content of the image stored on the video or digital media. Images stored on video or digital media, or copies of images stored on video or digital media, shall not be rendered inadmissible by the best evidence rule. Printed representation of images stored on video or digital media shall be presumed to be accurate representations of the images that they purport to represent.

Photographs as Evidence

The principal requirements to admit a photograph (digital or film-based) into evidence are relevance and authentication. Unless the photograph is admitted by the stipulation of both parties, the party attempting to admit the photograph into evidence must be prepared to offer testimony that the photograph is an accurate representation of the scene. This usually means someone must testify that the photograph accurately portrays the scene as viewed by that witness.

• Develop a Standard Operating Procedure (SOP), Department Policy, or General Order on the use of digital imaging. The SOP should include when digital imaging is used, chain of custody, image security, image enhancement, and release and availability of digital images. The SOP should not apply just to digital, but should also include film-based and video applications as well.
  
  
• Most importantly, preserve the original digital image. This can be done a variety of ways including saving the image file to a hard drive or recording the image file to a CD. Some agencies elect to use image security software.
  
  
• Digital images should be preserved in their original file formats. The saving of a file in some file formats subject the image to lossy compression. If lossy compression is used critical image information may be lost and artifacts introduced as a result of the compression process.
  
  
• If images are stored on a computer workstation or server, and several individuals would have access to the image files, make the files read-only for all but your evidence or photo lab staff. As an example, detectives could view any image files but they would not have rights to delete or overwrite those files.
  
  
• If an image is to be analyzed or enhanced the new image files created should be saved as new file names. The original file must not be replaced (overwritten) with a new file.

Check with Your Legal Advisor

When beginning a new procedure for collecting evidence or recording a crime scene, it is always prudent to check with your legal advisor. Consider the Federal Rules of Evidence, your state's rules of evidence, and other court decisions. Two court decisions regarding digital images include:

State of Washington vs. Eric Hayden, 1995: A homicide case was taken through a Kelly-Frye hearing in which the defense specifically objected on the grounds that the digital images were manipulated. The court authorized the use of digital imaging and the defendant was found guilty. In 1998 the Appellate Court upheld the case on appeal.

State of California vs. Phillip Lee Jackson, 1995: The San Diego (CA) Police Department used digital image processing on a fingerprint in a double homicide case. The defense asked for a Kelly-Frye hearing, but the court ruled this unnecessary on the argument that digital processing is a readily accepted practice in forensics and that new information was not added to the image.

About the Author

Steven Staggs is a forensic photography Instructor and has instructed over 3,000 crime scene technicians and detectives in crime scene and evidence photography over the past 17 years. He is a police manager having been in law enforcement for the past 29 years and is the author of the book, Crime Scene and Evidence Photographer's Guide.